1. Field of the Invention
The present invention relates generally to a method and a device for analyzing the moisture content of an oil. More specifically, the invention relates to an analysis of moisture content of an oil, such as an engine oil to be used in an engine mounted on a construction vehicle and so forth, or a working fluid to be used in hydraulic equipment, such as a hydraulic cylinder, or the like.
2. Description of Related Art
As is well known, when moisture, such as water, is comingled with the engine oil of a construction vehicle or the working fluid of hydraulic equipment, the characteristics of the oil can be so degraded by such moisture as to adversely affect the engine or the hydraulic equipment. Therefore, it is important to detect the moisture content of the oil.
Prior art moisture analyzing methods for the oil include a distillation method, Karl Fisher's volume titration method and Karl Fisher's coulomb titration method as discussed in JIS (Japanese Industrial Standard) K2275 "Testing Methods for Water Content of Crude Oil and Petroleum Products". Also, a hot plate method is known in the art as another technique for analyzing the moisture content of the oil. In the latter method, the moisture content is predicted by pouring several drops of oil to be analyzed on an iron plate preliminarily heated to a predetermined temperature (150.degree., for example), observing the water bubbles and bubbling behavior by eye, and comparing the observed amount of bubbles and bubbling behavior with references derived by the same method with respect to oil having a known moisture content.
The analyzing method recited in the above-mentioned JIS K2275 preferably employs a solvent and Karl Fisher's reagent. Also, this analyzing method requires equipment which is unacceptably large, and a glass instrument, solvent, and reagent. Thus, analysis is cumbersome, the equipment is too large to transport and the glass instrument is easily damaged when it is used at the site of engineering works.
Also, the foregoing hot plate method requires a qualified engineer for making a precise prediction. Furthermore, since it requires oil with a known moisture content, such method is not suitable for use at the site of the engineering works where the construction vehicle is active.